Spark plug



Dec. 7 1926.

P. E. SEASON SPARK PLUG Filed March 31, 1925 "FIG. 1

FIG. 3

INVENTOR HIS ATTORNEY Patented Dec. 7, 1926.

PER-LE E, BEASGYM Application. lll ld March s-cmu 170. 19,725.

This invention relates to new and useful improvements spark plugs.

it is one oi the principal objects of my invention to provide a spark plug: in which oil will not accumulate at the tiring points to foul it, but will be removed by the suction and cou'ipression e'llectcd by the inovii' piston ot the engine.

It is another object of my invent on to provide .u'icans for shedding water from the top oi? the spark plug so that it will not run down its sides to short circuit it.

fr still 'l'urther object or my invention is to provide tor the lower end of the central electrode of the spark plug a star or pointed contact piece to prolong; the life of the firing points.

it is still a turther object of the invention to provide a spark plug shell whose lower end is extremely thin to permit the heat of the engine to burn oft quickly any carbon that may stick to it. 7

Other important and incidental objects will be brought out in the following specification and particularly set forth in the subjoined claims.

In the accompanying drawings, Figure 1 side view of my in'iproved spark plug. gure 2 is a longitudinal sectional view en through the central portion of the plug. Figure 3 is a bottom plan view of my spark plug showing the siX-point star contact piece. And Figure l is an enlarged sectional view taken longitudinally through the lower end of the plug.

Referring to the accompanying drawings for a detailed (le criptiou of my invention, the numeral 1 designates a spark plug; shell which is preferably constructed of special grated 1r -k and a dome-shaped head 6 which is "formed with an overhanging run or ledge T to shed water dlrectly upon the hexagonal portion 2 of the plug and thus to prevent the ater from running down the sides of the cap to short circuit the plug. 1 and 2,)

The neck of the cap is formed with a wide central bore 8 which tapers at its upper end to a counterbore 9 of small diameter that projects through the head 6 of the cap. In sertible through the lower end oi the shell 1 into the bore 8 of the cap 5, is an elongated sleeve 10 preferably constructed of porcelain. This sleeve is thinned at its low or end with a shoulder 11 from which it tapers inwardly to its bottom. Located between the shoulder 11. oi the sleeve 10 and the top ot a recess formed in the lower end of the shell 1, are preferably two annular hollow gaskets 12, 12 that are preferably torined of flexible material for compression when the sleeve 10 is forced inwardly by means soon to be described.

Adapted to be inserted through the sleeve 10 and the cap 5 is central electrode 13 which is threaded at its top end to receive an assembly nut 14 and a top thumb nut 15. This electrode is also threaded. at its lower end to receive a stern extension nut 16 which bears against the top of a tapering recess 17 formed in the lower end oi? the sleeve 10. (See Figures 2 and 4.)

Secured between the extension nut 16 and a rivet head 18 formed on the lower end of the electrode 13. is a convex contact piece 19 that is preferably in the form of a six point-ed star: (See Figures 3 and l.) The pointed ends of this contact piece 19 when the plug) is assembled, project upwardly to points s hcicntiy near the lower end 015 the shell 1 to term spark gz aps tor the electr c current. A large number or" firingpoints is thus provided, to prolong the life of the tir- (1 See Figures aruiuinuui alloy. This shell has an upper ing part of the spark plug.

he); gone l portion 2 and a downwardly pro- The wall of the lower part of the stem 3 jecting stein which is tapering: and thread of the shell 1 surrounding the tapering lowed externally adjacent the hexagonal part 2 or end of the sleeve 1.0 is very thin so that ot the plug. (See Figure 1.) it may be sufticiently heated by the engine The top part of the hexagonal portion 2 to burn oil any carbon that may adhere of the plug is recessed to receive a split lock to it. washer l upon which seats the lower end of Formed in the lower end of the stem 3 oi a sleeve cap 5 preferably constructed of porthe shell 1 is a circumferential series of holes celuin. This cap preferably has an elon- 20 through which oil tree to escape from no the space between the wall ot the lower end of the stem 3 of the shell and the lower end of the sleeve 10. when the engine is in op eration, any oil which remains within this space will be withdrawn from it through the holes 320 in the shell by the compression and suction ettected by the moving piston. It is thus seen that in my improved spark plug no oil Will remain on the firing points to interfere with the explosion of the charge.

Another feature of advantage 01" my spark plug is that it is assembled from the bottom, after which the parts are tightly drawn together by the assembly nut 14.

Having described my invention, I claim:

A. spark plug comprising a metal shell, an insulating sleeve Within the shell, "formed at flexible packing between the said shoulder and the shell, a central electrode passing through said sleeve, and means on said electrode to compress said packing, the Wall of the shell below and near said packing being formed with a circumferential series of holes to exude oil from the packing when it compressed.

In testimony Whereoi I have hereunto set my hand this 28th day of March, 1925.

PERLE E. BFASGN. 

